I was reading the bondo thread and found some very good info in there. Now I wonder if we have a paint expert that can tell me if you have to top coat the 2k urethane primers or can you run them as is. I have my COE close to assembly stage in the 2k. I would like to run it that way but I don't want it absorbing a lot of moisture or have problems with UV. I would also like to avoid any added expense of epoxy primers if it isn't necessary. Thanks, Don
What are you using for a 2K primer? All primers are not the same, and you really shouldn't use a primer for a topcoat. That being said, some primers will fare better than others when exposed to the elements. If the vehicle is used sometimes and then stored inside where it's dry, it would probably fare pretty well as far as standing up to weather, moisture and sun/UV. One way to check if your primer is very susceptable to absorbing moisture, is to lay a wet rag on it, then check it every few minutes to see if the primer is discoloring from absorbing the water. If it starts absorbing in a few minutes, that's not good. If it takes a few hours, then you could run it on the street with certain cautions. I have sikkens colorbuild on my model A and I drive it, but seldom does it get wet and it goes in the garage when I'm done driving. No problems after about 4 years with somewhat limited exposure to sun and rain. The primer I used is high end--you get what you pay for. There are some good bang for the buck products out there. Another alternative is to use some single stage urethane (paint) as a "primer". You can usually pick up some mismatch mixed color at the local paint jobber store, maybe blend some colors or buy a little extra tint color to get something fairly decent, maybe flatten it a little and shoot it on for a "last" coat of primer. Paint is the best primer. You can sand it and still rerprime areas if needed, before you do the final paint job. This would do a much better of protecting and still let you finish sanding and prep without a lot of extra work. overspray
C'mon, Bill. I was waiting for you to get back with some info, maybe relative to this, on that Kirker primer you are trying. I'm not painting---just running the snowblower and banging on the puter. Right now, banging on the puter is much warmer. Anybody who uses good 2K hi-build primer has probably noticed that after you "break the skin", so to speak, when you first sand it, it will absorb water faster when wet sanding--depending on the primer (brand). I was hoping for some observations relating to this, so we could all benefit from each others' experience with different brands. Production shops (late model repair) probably don't wet sand as much as in the old days, but guys that do custom work probably have "wrinkly fingertips" every day.-----Can you say "Neutrogena" http://ajourneyoflife.com/articles/2007/07/10/neutrogena-norwegian-formula®-hand-cream/
Hi Guys: Urethane primers are very porous and must be topcoated. Even if it's with a sealer or a Epoxy primer. But your best bet is to paint it. Work the paint to get the finish you want. The Old Tinbasher
Haha, just kiddin ya pal. The Kirker has actually held up well. Its been outside since I sprayed it, about 6 mos now, and while the majority is covered by the car cover, the lower areas are getting their very own salt spray test from the town, haha. The cover blew off the other day and it doesn't look any different than it did during the summer. As far as lotions go... I reccomend something with a nice odor, but not too strong. I have a nice warm gingerbread scent.
As far as lotions go... I reccomend something with a nice odor, but not too strong. I have a nice warm gingerbread scent. [/QUOTE] I DID NOT SEE THAT COMING!
i find the better they fill, the more they take in moisture.....just a general rule though. i have had some jobs fare well out doors that were slicked on , but i would agree that primer isnt all that good for a final top coat if you like to use your car. rust can start forming and you dont even notice,untill its too late. i even get chalking with the expensive epoxies after awhile, id rather run paint skull
Those are the answers I am looking for. I used the Kirker high fill 2k primer. I suppose I will top coat it with epoxy primer, Maybe even paint it. Don
Depending on which epoxy you pick, most will absorb moisture like other primers, it might be a waste of money. Epoxy is not magic. A lot of epoxy primers are low to medium solids and are probably less protection than the Kirker 2K. Read the tech sheets on your primer choices and see how much solids are in the mix. You will see a LBS/per gal on some of the tech info. Although solids content is not the qualifier for protection, it's a start. Resins, the type of solid materials, mil thickness per coat, how many reccommended coats (also consider how much is removed when sanding) and how they rate as far as salt tests, corrosion resistance and what reccommended metal prep and topcoats determine the whole paint/primer film protection capability. Some primer/paint discussions: http://www.jalopyjournal.com/forum/showthread.php?t=293553&showall=1 http://www.jalopyjournal.com/forum/showthread.php?t=297587&showall=1 http://www.jalopyjournal.com/forum/showthread.php?t=380585&showall=1 http://www.jalopyjournal.com/forum/showthread.php?t=364032 http://www.jalopyjournal.com/forum/showthread.php?t=350749&showall=1 http://www.jalopyjournal.com/forum/showthread.php?t=282299 http://www.jalopyjournal.com/forum/showthread.php?t=244070&showall=1 http://www.jalopyjournal.com/forum/showthread.php?t=182387
Thats what I used on my own car thats sitting outside that I mentioned above. The stuff really isn't bad for the price. That being said, no primer will protect like paint. Instead of spending money on an epoxy, why not just get a single stage and either flatten it or use it as is?
I'm just a crappy painter.In 1997 I painted my 37 Chevy pu with Dupont red epoxy primer over pretty clean bare steel that was sanded and acid washed to get rid of as much surface rust as possible.. I sold the truck last year to a guy in Florida.When I sold it the epoxy primer had faded slightly,but no signs of rust or chalking.
Update on the '37. It's been getting beatup by the Florida sun for sixteen months now (daily driver, not garaged) and it's fading some but still no rust or chalking. I'll slap more epoxy primer on as needed. I clean it from time to time with "Wash Wax All"
From an automotive paint sales (tech) point of view all primers (surfacers & sealers) contain talc which we all know absorbs moisture.2k products (that is a catalized products) tend to hold up much better with out a top coat compared to air dry products. Lower solid content sealers will hold up better that higher solid sealers because they have a greater resin to talc ratio in most cases. but if you ask a paint company they will tell you all primers MUST be topcoated in a certain amount of time to keep them from absorbing moisture.
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